Code No.C1750: ACC/FCM-ECU Voltage out of Range


caution
  • When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine cannot be started. Register the encrypted code as described in GROUP 54A, Immobilizer System - How to Register Key ID .)

OPERATION



DIAGNOSIS CODE SET CONDITIONS




  • Voltage between the battery and ETACS-ECU: Less than 9.0 V
  • Voltage between the battery and ETACS-ECU: More than 16.0 V

PROBABLE CAUSES



  • Battery failure
  • Loose battery terminal
  • Malfunction of charging system
  • Malfunction of ETACS-ECU (power supply circuit system)
  • Damaged harness wires and connectors
  • Malfunction of ACC/FCM-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check the battery.
Refer to GROUP 54A - Battery Test .

Q. Is the check result normal?
Go to Step 2
Charge or replace the battery.

STEP 2. Check the charging system.
Refer to GROUP 16 - Charging System .

Q. Is the check result normal?
Go to Step 3
Repair or replace the charging system component(s).

STEP 3. Voltage measurement at ACC/FCM-ECU connector
(1)Check the connector
(2)Disconnect the connector.
(3)Turn the ignition switch to the "ON" position.
(4)Measure the voltage between terminal IG and body earth at the wiring harness side.
OK: System voltage

Q. Is the check result normal?
Go to Step 4
Repair the defective connector or the wiring harness (power supply line).

STEP 4. Check the wiring harness between ACC/FCM-ECU connector GND terminal line and body earth line .
Check the earth line for damage circuit.

Q. Is the check result normal?
Go to Step 5
Repair the defective the earth line.

STEP 5. M.U.T.-III data list.
Check the following data list (Refer to ).

  • Item No.01: ECU power supply voltage

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Replace the ACC/FCM-ECU (Refer to ).